1. Technical Field
The present invention relates to an electronic shift lever assembly, and more particularly, to an electronic shift lever assembly which can select a gear position by sensing the movement of a shift lever in forward, backward, right and left directions using hall sensors.
2. Background Art
A vehicle transmission changes gear ratio according to vehicle speed so that engine can rotate at a constant speed. The gear ratio can be changed by manipulation of the shift lever of the transmission. The transmission is generally classified into a manual transmission in which gear position is manually changed by a driver and an automatic transmission in which gear position is changed automatically according to vehicle speed when a driver selects a drive (D) mode.
In addition, a “sports mode” transmission, which can manually and automatically changes the gear position, is used. That is, a manual transmission which allows a driver to manually change the gear position to a higher or lower gear position while driving in automatic transmission mode can be provided along with an automatic transmission.
A driver may select one of the gear positions of an electronic transmission, such as park (P), reverse (R), neutral (N), drive (D), and ‘2’ and ‘1’ gears at which engine brake can be applied. There have been attempts to apply a hall sensor, which uses a magnet, to select one of the gear positions. Since the hall sensor can convert a magnetic force into an electrical signal, it senses the selected gear position using the electrical signal. That is, the position of the shift lever can be identified using an electrical signal, mainly a voltage, sensed by the hall sensor.
Conventional systems for sensing the position of a shift lever using a hall sensor are disclosed in U.S. Pat. Nos. 6,550,351 and 6,305,075.
The conventional systems use a linear hall sensor or a switch hall sensor to sense the position of the shift lever which moves in one direction. However, it is difficult to effectively apply the linear hall sensor or the switch hall sensor when the shift lever moves not only in linear path but also in complicated paths.
In addition, a separate sensor unit must be installed at each shift position (P, R, N or D) and each select position (+, −) in order to sense each of the shift and select positions. Consequently, the structures of the conventional systems become complicated, causing high manufacturing costs.
Moreover, since the conventional automatic gear transmissions, which drive manual valve using cable tension as the position of the shift lever is adjusted by a driver, driving mode can be incorrectly selected when the driver makes a mistake while driving or is inexperienced in manipulating the shift lever.
Furthermore, the driver may not able to select a desired mode due to aging of the cable, and fuel efficiency may decrease by heavy weight of vehicle parts.
Also, the conventional automatic gear transmissions, generally, have a large size so as to cause the utilization of vehicle space to be limited.